POLYANILINE COMPOSITES AS THERMOELECTRIC MATERIALS

Abstract

Polyaniline (PANI) and PANI based composites are receiving a special interest as thermoelectric materials following the promising reports on PANI/Carbon nanotube (CNT) composites. However, main drawback of PANI and PANI based composites is their low electrical conductivity. In this thesis, thermoelectric properties of PANI and PANI/CNT composites were studied. First, we synthesized highly ordered PANI by frozen polymerization to enhance the conductivity. Secondly, we proposed to use amine functionalized CNT (a-CNT) to form a-CNT/PANI composites. Amine functionalization is expected to improve the electrical transport properties of the composite. However, this improvement was accompanied with a loss of Seebeck Coefficient due to the increase in carrier concentration. Consequently, we proposed to introduce SiO2, n-type TiO2 and p-type TiO2 to control the carrier concentration. Results show that the carrier concentration was reduced, and both Seebeck Coefficient and power factor were enhanced by the formation of ternary composites, especially a-CNT/PANI/p-type TiO2.